The present invention relates generally to a protective sheath for winged needles commonly used for intravenous infusion sets, scalp-vein sets, and blood collection sets, as well as for fistula needles used in blood dialysis. More particularly, the present invention relates to an improvement to such protective sheaths.
A well known problem in the health care industry is the danger posed by accidental needlesticks from contaminated or used syringes and intravenous equipment. Health care professionals as well as maintenance personnel who dispose of used medical equipment face exposure to hepatitis, AIDS and other diseases which can be transmitted by needlesticks from such contaminated or used equipment. A solution to this problem can be found in U.S. Pat. No. 4,941,881, to Masters et al, granted Jul. 17, 1990 wherein the intravenous infusion set comprises a length of tube having a needle at one end of the tube, flexible wings adjacent the needle and a sheath slidably disposed on the tube and adapted to be slid over the needle to cover the needle after it has been used. The sheath comprises a tubular body having a longitudinally extending slot commencing at the forward end of the sheath adapted for receiving therein the wings in a folded-up configuration so as to allow at least part of the sheath to be slid past the wings to cover the needle. The sheath also includes a cutout at the rearward end of the slot for engaging the wings when they are released so as to lock the sheath in position covering the needle. In operation, following removal of the needle from the patient, the user grasps the wings together with one hand and with the other hand slides the sheath forwardly so that the wings enter the slot and are engaged in the cutout therefor and the sheath covers the needle.
An improvement to the protective sheath of the Masters et al patent can be found in U.S. Pat. No. 5,330,438, to Gollobin et al, granted Jul. 19, 1994. In the improved protective sheath of the Gollobin et al patent, there are provided at least three longitudinally extending slots commencing at the forward end of the sheath each having a width slightly less than the width of one of the wings and each terminating towards the rear of the sheath in a cutout having a width at least equal to the width of one of the wings. The sheath is provided at its rearward end with a knurled, generally cylindrical, annular base by which the sheath may be easily grasped. In operation, the user grasps the sheath at the rearward annular base thereof with one hand and pulls on the tube with the other hand to retract the needle within the sheath with each wing of the needle entering a slot and engaging a cutout to lock the sheath in position covering the needle.
It is a primary object of the present invention to further improve the protective sheaths disclosed in the above discussed U.S. Pat. Nos. 4,941,881 and 5,330,438, the subject matter of these patents being incorporated herein by reference, whereby the protection afforded against needlesticks is enhanced and the manipulation of the protective sheath in covering the used needle is facilitated.
The above object, as well as others which will hereinafter become apparent, is accomplished in accordance with the present invention by the provision of a needle set consisting of a length of tube having a needle at one end of the tube, a pair of outwardly projecting flexible wings adjacent the end of the tube with the needle and a sheath slidably disposed on the tube and adapted to be slid over the needle to cover the needle after use. The sheath is a hollow, generally tubular body having a forward end oriented toward the needle and a rearward end oriented away from the needle. The tubular body has at least one longitudinal slot and preferably at least three longitudinal slots commencing at the forward end and extending toward the rearward end for receiving the outwardly projecting flexible wings. The rear end of each slot is provided with engaging means for the outwardly projecting flexible wings in the form of cutouts so as to lock the sheath in position covering the needle after the needle has been retracted therein. The improvement consists in providing the protective sheath at or near the rearward end thereof with an outwardly projecting, at least partially annular guard. The provision of such an outwardly projecting guard at the rearward end of the protective sheath prevents the user""s hand from slipping forwardly on the sheath when the user grasps the sheath and pulls the tube therethrough. This is particularly beneficial in those situations where the user is wearing latex gloves which may be slippery or wet. Furthermore, such a guard also insures that the user grasps the protective sheath at the rear thereof and not over the portion with the slot or slots which could collapse the sheath on the tube therein clamping the same and preventing movement thereof.
The foregoing and related objects are also attained with such an improved protective sheath for a wing type needle having the aforementioned construction.